061020 4CD meeting R.Yamada 1

Thoughts on4CD (4th Concept Detector)

Solenoid System

based on Alex Mikhailchenko’s Basic Design

Ryuji Yamada

October 20, 2006

061020 4CD meeting R.Yamada 2

Problems with 4CD Solenoid • 4CD’s overall dimensions

comparable with others• 4CD’s overall weight ~2000 tons ?

much lighter than others• Overall Stored Energy 2.7 GJ,

biggest among HEP detector Solenoidssimilar to CMS’s 2.6 GJ

• Inner Solenoid, Outer Solenoid, 2x End Cover, and 2x Beam Correction Solenoid

• 4 major components should be in Series Operation to protect from Leakage Flux Problem

061020 4CD meeting R.Yamada 3

Inner Solenoid• Inside Field 3.5 Tesla• Required Field Uniformity TPC Requirements ?

∆B/B < 5 x 10-4 in r <1.4 m, z< ± 1.5 m.• Construction Method

Extensive Design Studies needed

Indirect Cooling or Pool Boiling• Sharp Peak Field 17 – 10 Tesla or 6 Tesla• Superconductor beside NbTi, used for all others • Enormous Compression Force at End Rings

Related to the Peak Field

20,000 tons for 6 Tesla peak field

061020 4CD meeting R.Yamada 4

Inner Solenoid• Reduction of Peak Field by Field modification • Selection of Superconductor

Nb3Al, Nb3Sn, or NbTi Not High TC now

• Design of stronger Vacuum Vessel ?

We can use Material as thick as needed

Pool Boiling Design by Bob Wands • Small Inner Model Magnet (2m dia. 4 m long)

together with Outer Model Magnet (size ?)

to be made, which could be used

for testing full size TPC Unit

061020 4CD meeting R.Yamada 5

Inner SolenoidThin Wall Design (still to be optimized)• Central Part + 2 End Parts• Reduce Peak Field as small as possible

12 Tesla or 6 Tesla (all NbTi)• Central Part similar to CMS design

NbTi 4 Layers, or 6 Layers ?• 2 End Parts

Nb3Al or Nb3Sn for B>8 Tesla, or NbTi• Strong Support Cylinder with compartments

may be needed, if Pool Boiling is used

061020 4CD meeting R.Yamada 6

Inner Coil AM’s Original Geometry

Max Flux Density

17.2 Tesla

Current Density (106A/m2)

Inner Solenoid 38.6

Edge Ring 231.6

Outer Solenoid 9.9

061020 4CD meeting R.Yamada 7

Inner Coil Edge Ring Extended

Max Flux Density

11.8 Tesla

Current Density (106A/m2)

Inner Solenoid 40.67

Edge Ring 134.2

Outer Solenoid 14.08

061020 4CD meeting R.Yamada 8

Inner Coil Distributed Current

Max Flux Density

6.2 Tesla

Current Density (106A/m2)

Inner Solenoid 32 ~39

Edge Ring 61 ~73

Outer Solenoid 7.3

061020 4CD meeting R.Yamada 9

Outer Solenoid• 12 m dia., 12 m long, 1.5 Tesla

• World largest volume Solenoid ?

• Technically Feasible solenoid

• No Transportation method exist ?

• Components to be build at Factory

• To be assembled on Surface at Site and

to be lowered into Pit

061020 4CD meeting R.Yamada 10

End Covers• Dia. of Vacuum Vessel 12 m• Technically Feasible ?

Total Outward Force ~4700 tons by Bob.Thermal Support will be problem without Huge Heat Loss

• No Transportation method• Components to be build at Factory• Each End Cover should be assemble in a

common Vacuum Vessel on Surface and lowered into pit

061020 4CD meeting R.Yamada 11

Detector Assembly• Whole Detector, including Solenoid System

mounted on Movable Platform like D0 Detector

for Push-Pull Operation• Outer Solenoid mounted on Carriage and fixed• Inner Solenoid suspended inside Outer Solenoid• Detector Components mounted

inside Inner Solenoid• Muon Detector inserted between two Solenoids• Each End Cover is mounted on Carriage, and

moves in axial direction

061020 4CD meeting R.Yamada 12

Things to be done• Strong Thermal Support with reasonable Heat Loss

for Inside Ring Coils of End Cover should be designed first

• Peak Field of Inner Coil should be made around

6 Tesla• Then 6 layer coil will work with NbTi• Optimize the Design

• Parameter Table of all Components of 4CD